Apparently High Service of Water 5 



One of the most striking features of the arid sec- 

 tions of the United States, which attracted the writer's 

 attention during his travels through the West, was this 

 apparently greater service of water in crop production 

 than is realized in the more humid climate of the east- 

 ern section of this country. Reasoning from general 

 principles, one is naturally led to anticipate that in an 

 exceptionally dry atmosphere and under a clear sky, 

 such as we have in the western United States, the rate 

 of evaporation, both from soil and vegetation, would 

 be exceptionally rapid, and hence that enormous quan- 

 tities of water would be required in crop production, 

 when compared with the demands of crops under more 

 humid conditions. 



Such, however, does not appear to be the case, and 

 it is this fortunate relation which makes it possible 

 for larger areas to be placed under irrigation with the 

 limited amounts of water than would be possible were 

 the conditions of the soil more like those of humid 

 climates. 



It is not easy to assign a thoroughly satisfactory 

 set of reasons for this marked difference without a 

 more detailed study of the field conditions than has 

 yet been made. It seems quite probable, however, that 

 prominent among the reasons to be assigned for these 

 differences is the one to which reference has already 

 been made : namely, the texture of the soil, which 

 allows the water to distribute itself evenly and rela- 

 tively deep in the soil, and it does not return 

 readily and rapidly by capillarity to the surface to be 

 lost. 



OF THE 



UNIVERSITY 



OF 



